PARENT SESSION
Poster Session #6: Conservation Ecology.
Monday, August 6, 2001. Presentation from 3:30 PM to 5:00 PM. Exhibition Hall
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Patch and landscape characteristics associated with the distribution of woodland amphibians in an agricultural landscape.
Weyrauch, Shauna1, Grubb, Thomas1, 1
ABSTRACT- In fragmented landscapes, species richness within patches may decline over time if extirpations are not offset by colonizations. Agricultural landscapes with scattered woodlots are common in the Midwestern United States. We studied the pond-breeding amphibians of a 15,000-ha study landscape in rural northern Ohio, to investigate the relationships between amphibian distributions and pond, woodlot and landscape characteristics. We surveyed 25 woodlots and one area of continuous forest for amphibians in 1998, 1999, and 2000. Woodlots were surveyed at least three times per year using four methods: visual encounter surveys, auditory surveys, egg mass identification, and larval identification. We quantified 26 habitat characteristics for use in our models. We used stepwise multiple regression to investigate the relationship between amphibian species richness and habitat characteristics, and logistic regression to create models for the occurrence of individual species. The surveyed woodlots varied in area from 0.73 to 31.10 ha (mean = 9.88 ± 7.09 ha), and each woodlot contained at least one pond (mean = 2.36 ± 1.68). We identified 13 species of amphibians. The most common species were Ambystoma texanum and Rana sylvatica (24 and 22 locations, respectively). The mean number of species found per woodlot was 5.2 ± 2.8 (range, 1-9). Species richness was most significantly correlated with characteristics of pond size and hydroperiod. Woodlots within agricultural landscapes are important refuges for amphibians.
KEY WORDS: habitat fragmentation, amphibians, landscape ecology, conservation